code: def test_objectmapper(self):
      df = pdml.ModelFrame([])
      self.assertIs(
          df.kernel_approximation.AdditiveChi2Sampler,
          ka.AdditiveChi2Sampler,
      )
      self.assertIs(df.kernel_approximation.Nystroem, ka.Nystroem)
      self.assertIs(df.kernel_approximation.RBFSampler, ka.RBFSampler)
      self.assertIs(
          df.kernel_approximation.SkewedChi2Sampler,
          ka.SkewedChi2Sampler,
      )
  
file_path: pandas-ml/pandas_ml/skaccessors/test/test_kernel_approximation.py
imports: import pytest
  import sklearn.datasets
  import sklearn.kernel_approximation
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 1 for calling the TestKernelApproximation obj's underlying member method code with example usage: obj.test_objectmapper() without return types